The song is the Dandelion Junk Queen's cover of A Las Barricadas, containing a rough translation of the original Spanish folk song as the second verse.

In this PMV King Sombra is Adolf Hitler, Nightmare Moon is Francisco Franco, and the Apple Family are the Anarcho-Communists and the Anarcho-Syndicalists of C.N.T and F.A.I.

Here's a link to the original lyrics and the original version of the song: https://www.marxists.org/subject/art/music/lyrics/es/a-las-barricadas.htm

Yes... This song does indeed represent my political opinion, but despite the nature of the song and myself, I won't allow any political BS to fill the comments, if you attempt to start an argument you comment is being deleted. Solidarity Forever!